Pipe couplings are described in DE 27 44 739 A1, U.S. Pat. No. 4,174,125 A and EP 1 102 943 B1, for example, wherein reference is made to the aforementioned published prior art with respect to the basic composition of a pipe coupling and the use thereof.
Usually a lubricant, such as bentonite, is applied to the outside wall of the pipes for pipe jacking so that the pipes can be pushed better into a tunnel or the like. To this end, an opening is introduced into the wall of the pipe, through which the lubricant can be injected onto the outer wall of the pipes from inside the pipes. This opening in the wall, however, has the disadvantage of weakening the structure of the pipe, whereby considerable stability and strength problems, in particular with respect to the internal pressure during operation of the pipe, can occur.